Stop-motion mechanism for sewing-machines



(No Model.) 3 Sheets-Sheet 1.

H. H. CUMMINGS. v

STOP MOTION MECHANISM FOR SEWING MACHINES.

No. 391,769. Patented 001;. 23, 1888'.

(No Model.) 3 Sheets-Sheet 2.

H. H. CUMMINGS. STOP MOTION MBGHANISM FOR SEWING MACHINES.

No. 391,769. Patented Oct. 28, 1888.

(No Model.) 3 Sheets-She t 3,

H. H. CUMMINGS.

STOP MOTION MEGHANISM FOR SEWING MACHINES.

atented Oct. 23, 1888.

WITNEESEE- F75.

lllnrrnn STATES PATENT tries.

HENRY H. CUMMINGS, OF MALDEN, ASSIGNOR TO THE UNION BUTTON SE'WINGMACHINE COMPANY, OF BOSTON, MASSACHUSETTS.

STOP-MOTION MECHANISM FOR SEWING MACHINES.

SPECIFICATION forming part of Letters Patent No. 391,769, dated October23, 1888.

Application filed May 6, 1887. Serial No. 238,001. (No model.)

To all whom it may concern:

Be it known that I, HENRY H. CUMMINGS, of Malden, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in Stop-Motion Mechanisms for Sewing'Machines, ofwhich the following is a specification.

My invention relates to sewing-machines of the class employing devicesfor automatically arresting the operation of the main shaft afterapredetermined number of revolutions thereof have been made.

It is the object of my invention to provide simple and efficientmechanism for accomplishing the purposes mentioned, located within thestandard or support for the overhanging arm, where it may be near to theclutch mechanism, convenient of access, and at the same time be out ofthe way of danger of damage by contact with other things or parts of themachine, as will be hereinafter fully and clearly set forth, andparticularly pointed out in the claims.

Of the drawings hereto annexed and forming a part of this specification,Figure 1 rep resents a perspective view of my invention, only so much ofa sewing-machine frame being shown as is necessary to illustrate therelationship or connection of my improvements therewith. Fig. 2 is arear elevation of the same. Figs. 3 and 4 are sectional views on theline a z of Fig. 2, looking in the direction of the flight of the arrowmarked thereon, showing the parts in different positions. Fig. 5 is afront elevation of portions of the machine picturcd in Figs. 1 and 2,showing my improvements as applied thereto. Figs. 6 and 7 are sectionalviews on the line 3 3 of Fig. 5, looking in the direction of the flightof the .roIarrow pictured thereon, and showing the parts thererepresented as in different positions and corresponding to the positionsportrayed in Figs. 3 and 4.

Similar letters of reference indicate similar parts in all of thefigures.

A represents the bed of the machine; B, the overhanging arm; 0, thestandard supporting the same; D, the main driving-shaft, and E thedriving pulley, adapted to receive a band to rotate shaft D and operatethe machine.

The parts just described may be of the form represented or of any otherform common in the construction of sewingmachincs.

The driving-pulley E is adapted to turn loosely on shaft D, but isconstructed to be connected therewith by means of pins or lugs F,projecting laterally from the pulley coming in contact with aclutch-dog, G, swiveled or pivoted to shaft D, as most clearlyrepresented in Figs. 6 and 7. The outer end of the clutch-dog G isnormally held pressed toward the adjacent face of the pulley by means ofa spring, H, surrounding the pivot-pin I.

J represents a lever pivoted at K to the standard 0, and having aportion, L, bent at right angles thereto, and extending behind or alongthe rear of the standard, to which angular portion is attached a finger,M, extend ing forward and upward, and-when raised by the lever-into thepath of travel of the outer end of dog G, so that said dog may engagethe inner inclined face of said finger and be drawn back from engagementwith the lugs F, and thus unclutch pulley E from the driving'shaft andstop the machine.

The mechanism thus far described, except as to the lever J and to therelationship to other devices, is not essentially different from thatshown and described in the patent granted to Driscoll, December 16,1884, No. 309,209, to which patent reference may be had.

Angular part L of lever J has a cam piece or block, a, formed on orconnected therewith, having an inclined face, 4, and an angular point orprojection, 5, as shown in Figs. 1, 6, and 7.

1) indicates a latch-lever pivoted atits lower end, as at c, to thestandard 0, and having the outer end of a tripping-arm, (1, extendingthrough and a short distance beyond to its upper free end, (see Figs. 1,2, and 5,) which pro jecting end (1' of tripping'arm d is adapted torest on cam-piece a,-and as the latter is moved ride up its inclinedface 4 and be caught or locked on the angular point or projection 5, asseen in Fig. 6. Trippingarm (1 extends horizontally through the rear ofstandard 0,

downward, and again horizontally outward within said standard, where aplate, 0, is secured thereto, which plate is provided withlaterally-projecting fingers f g, for a purpose to bepresently'explained.

it indicates a lever pivoted on a stud, z. to the inner forward side ofstandard 0. Said lever h is bifurcated or forked at its upper end, so asto embrace a cam,j, on main shaft D, and be thereby rocked on its pivotZ. A pawl, 7c, is pivoted on the lower end of lever h and adapted toengage the teeth of ratchet-wheel Z, adapted to turn loosely on stud Z.Said ratchet-wheel is provided with holes m, corresponding in number andposition with the teethof the wheel, which holes are adapted to receivea laterally-projecting pin or stud, a, of a lug or dog, 0, and so befixed at any desired point on said wheel.

1) representsa holdingpawl pivoted to stud P on the side of standard 0,and arranged to engage the teeth of ratchet-wheel Zand hold the samefrom turning backward, or in a direction opposite to the arrow markedthereon, when an intermittingly rotary movement is being imparted to theratchet-wheel by the operation of pawl k. Springs q'r, respectivelycoiled about and secured to the pivotal studs and bodies of pawls 7c andp, respectively operate with a tendency to hold said pawls in engagementwith the teeth of ratchetwheel Z.

Finger f of plate e extends out alongside of and in contact with thelower end or tail of pawl 19, and the tail or rear end of pawl restsagainst the front cam-shaped face of the tail of pawl p. Finger 9 ofsaid plate 0 extends laterally into the path of travel of lug or dog 0.

The operation of my invention maynow be described as follows: Supposingthe normal position of ratchet-wheel Z to be that represented in Fig. 4,and the dog 0 to be fixed thereon, as pictured in said lastlmentionedfigure, the machine may be set in operation by raising the handle oflever J,Which will depress finger M and allow one of the studs F onpulley E to come in contact with dog G and so rotate the main shaft.When finger M was depressed, as just explained, the upper end oflocking-lever b was carried backward in the direction of the arrowmarked thereon from the position represented in Fig. 7 to that portrayedin Fig. 6, and the projecting end d of tripping-arm d brought over thepoint or corner 5 of cam-piece a, whereby said finger M is looked in itsdepressed position. This movement of locking-lever b is accomplishedpartly by the tension of the springs q and r of pawls k and p operatingthrough said pawls on finger f of plate 0, secured to tripping-lever (Z,and partly by the mere gravity of said lever b. By the movementalso justdescribed plate e on tripping-lever d was brought into positionrepresented in Fig. 3, so as to permit pawls k and p to engage the teethof ratchet-wheel Z, and the latter be rotated or moved one tooth at eachrotation ofmain shaft D, through the medium of cam j, lever h, and pawlk, and this operation willcontinuc until dog 0 is brought intocontactwith finger g of plate 6, as represented in Fig. 3, when at thenext movement of the ratchet-wheel said dog will draw back said fingerand throw the projecting end d of tripping-arm (1 off point 5 ontoincline 4 of campiece a,when, by the action of spring r operating on theend of lever L to draw it upward, said inclined face 4 of cam-piece awill throw locking'levcr I) back in a direction opposite to the flightof the arrow, carrying fingerf down against and so as to throw forwardthe tail of pawl 17, which will at the same time be brought into contactwith the tail of pawl Zr, and both pawls thus thrown out of engagementwith the ratchetwheel Z. The pawls k and 1) being thus freed from theteeth of ratchet-wheel Z, the latter is returned to its normal position(see Fig. 4.) by the action of a watch-spring, 8, (shown in dotted linesin Figs. 8 and 4,) coiled around stud t on the inner side ofratchet-wheel Z, and having one end secured to said stud and the otherend to said ratchet-wheel.

In Figs. 1, 3, and 4 portions of two teeth of ratchet-wheel Z are cutaway in such manner as, while not affecting the functions ofholding-pawlp, (which is wider than pawl 7c,ex-

tending across the entire width of the ratchet wheel,) to renderinoperative and ineffectual the movement of pawl 70 when they arriveopposite thereto, (which is as far as the ratchetwheel can with safetybe turned,) thus preventing breakage of any of the parts connected withthe ratchet-wheel in case the pawls are not tripped and the machine isleft running. This mutilation of the teeth of ratchetwheel Z is done forthe purpose of providing against the further turning jof saidratchetwheel in the event of a failure from any cause in the operationof the tripping devices, and so avoid the breaking of spring 8 or otherparts of the machine.

When lever J was released and angular part L drawn upward by spring 1",as has been described, finger M was also drawn upward into the path oftravel of dog G, which latter device, coming in contact with the innerinclined face of said finger, was drawn away from contact with studs Fon pulley E, permitting said pulley to run free on shaft D, theengagement of dog G with finger M stopping the rotation of said shaft.

By the construction and arrangement of 1 parts described a very simple,compact, and effective stop-1notion mechanism for sewingmachines isprovided, and by locatingit within the standard of the overhanging armit is placed out of the way of liability of damage by contact with otherthings, space not otherwise occupied is utilized, and it is at the sametime made convenient of access.

It is obvious that the form and arrangement of parts comprising myimprovements may be varied within the limits of mechanical skill withoutdeparting from the spirit or nature of the invention.

Having thus described my invention, what I claim is 1. The combination,with the main shaft, its driving-pulley, and the dog engaging lugs ofsaid driving-pulley, of the hollow standard and arm, the lever fnlcrnmedon said standard, and having a right-angular end provided with a campiece or block, a, the finger connected to said lever, the tripping-armengaging said cam piece or block, and the tripping mechanism connectedto said tripping-arm, which, together with said tripping mechanism, islocated in said hollow standard, substantially as shown and described.

2. The combination, with the main shaft, its driving-pulley,and clutchmechanism for connecting the driving-pulley with and disconnecting itfrom the main shaft, of the lever J, having the right-angular endprovided with a cam piece or block, a, the finger connected to saidlever, the latchlever b, the trippingarm connected at one end to saidlatch-lever, the plate 0, having the fingersfg, the main shaft havingthe cam secured thereon, the lever operated by said cam, the pawlpivoted to and operated by said lever, the ratchet-wheel,with which saidpawl is adapted to engage, aholding-pawl, also adapted to engage saidratchetwheel, and a dog on said ratchet-wheel adapted to be brought intocontact with one of the fingers of said plate e, as set forth.

3. The combination, with the main shaft carrying a cam, thedriving-pulley, the clutch mechanism for connecting the driving-pulleywith and disconnecting it from said main shaft, the lever having arightangular end provided with a cam piece or block, and thetripping-arm having the plate 6, provided with two fingers, f g, of theratchet-wheelhaving a series of holes, m, and secured on astud, b, thelug or dog 0, having alaterally-projecting pin orstud, a, designed toenter one of said holes, the coil-spring secured to said ratchet wheeland to the stud b, the lever h, having the upper bifurcated end, thepawl pivoted to and operated by said lever, and the holdingpawl adaptedto engage said ratchet-wheel, substantially as shown and described.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 11th day of April, A. D.1887.

HENRY H. CUMMINGS.

\Vitnesses:

ARTHUR W. GRossLnY, O. F. BROWN.

